JP6060373B2 - Centrifugal fan and air conditioner equipped with the same - Google Patents

Description

  The present invention relates to a centrifugal fan and an air conditioner equipped with the centrifugal fan, and more specifically, for a centrifugal fan used in a blower provided in a humidifier, the accuracy of joining the shroud and main plate of the centrifugal fan by ultrasonic welding is improved. It relates to what you can do.

  A centrifugal fan used in a blower provided in an air conditioner includes a first blade portion and a second blade portion, and the first blade portion includes a main plate having a fixed rotation shaft, and the main plate. A plurality of blades extending from the first flat end portion, which is a horizontal surface located on the outer peripheral side of the main plate, and a center side of the main plate from the first flat end portion. A second flat end that is a horizontal plane, and the first flat end and the second flat end between the first flat end and the second flat end. The second blade portion includes an annular shroud disposed opposite to the main plate, and an inner surface of the shroud includes the first flat end portion. And a second flat end portion and a fixed portion in contact with the connecting end portion, the first blade portion of the first blade portion A Tintin portion and the fixing portion of the second of said second blade section and a connecting end portion and the flat end is known that welded ultrasonically (e.g., see Patent Document 1).

JP 58-35296 A

  As described above, the centrifugal fan of the conventional air conditioner combines the first blade portion and the second blade portion by ultrasonic welding. When the welding surface is a curved surface, the horizontal direction and the vertical direction are in contact with the direction in which a force is applied during ultrasonic welding.

  When the vertical direction is in contact with the direction in which the force is applied during ultrasonic welding, when the blade vibrates in the horizontal direction while applying a force in the direction of the rotation axis to the blade extending from the main plate, the blade is warped. There is a problem that the balance of the centrifugal fan is lost due to the main plate and the shroud being combined in a deformed state.

  Therefore, an object of the present invention is to improve the balance of the centrifugal fan by suppressing the deformation of the blades during ultrasonic welding.

And in order to achieve this object, the centrifugal fan of the present invention comprises a first blade portion and a second blade portion, and the first blade portion includes a main plate to which a rotation shaft is fixed, The blade includes a plurality of blades extending from the main plate. At the tip of the blade, a first flat end located on the outer peripheral side of the main plate and an inner end of the first flat end from the inner end of the main plate The second blade portion includes an annular shroud disposed opposite to the main plate, and a blade fixing portion that fixes the blade protruding from the inner surface of the shroud. The blade fixing portion includes a hollow convex portion, a first support extending from the convex portion, and sandwiching the first flat end portion of the blade and at least a part of the connecting end portion. And the second support portion, and the first support portion and the second support portion provided between the first support portion and the second support portion. A first horizontal flat surface section contactable to a flat end portion of the 1, consists of a first of the coupling surface portion extending from the inner end of the horizontal flat surface portion toward the center of the shroud, of the first blade portion said connection end provided with a space between the connection surface of the second blade portion, wherein the first flat end, the first projecting from the flat end, the first A welding projection is provided in which the first flat end portion of the blade portion and the first horizontal flat surface portion of the second blade portion are ultrasonically welded .

According to the present invention, the centrifugal fan of the present invention includes a first blade portion and a second blade portion, and the first blade portion extends from the main plate to which the rotation shaft is fixed, and the main plate. The blade has a first flat end located on the outer peripheral side of the main plate, and extends from the inner end of the first flat end toward the center of the main plate. The second blade portion includes an annular shroud disposed to face the main plate, and a blade fixing portion that fixes the blade protruding from the inner surface of the shroud, The blade fixing portion includes a hollow convex portion, a first support portion and a second portion extending from the convex portion, and sandwiching the first flat end portion of the blade and at least a part of the connecting end portion. And the first flat end provided between the first support portion and the second support portion. First horizontal flat surface section can be made this first coupling surface extending from the inner end of the horizontal flat surface portion toward the center of the shroud, and the connecting end portion of the first blade portion, said A space portion is provided between the second blade portion and the connection surface portion, and the first flat end portion protrudes from the first flat end portion, and the first blade portion includes the first blade portion. A welding protrusion is provided in which a flat end portion and the first horizontal flat surface portion of the second blade portion are ultrasonically welded .

  As described above, when ultrasonic welding is performed, a space portion is provided between the connection end portion of the first blade portion and the connection surface portion of the second blade portion, and the first blade portion and the second blade are provided. Since the portion is in contact only with the horizontal plane, the balance of the centrifugal fan can be improved by suppressing the warpage of the blades and reducing the deformation of the main plate and the shroud.

The perspective view which looked at the air conditioner of Embodiment 1 of this invention from the case front side A perspective view of the air conditioner viewed from the back side of the case Vertical section of the air conditioner Perspective view of centrifugal fan of the air conditioner An exploded perspective view of the centrifugal fan of the air conditioner Perspective view of blade fixing part of centrifugal fan of same air conditioner Enlarged view of blade and blade fixing part before welding of centrifugal fan of the air conditioner Enlarged view of blade and blade fixing part after welding of centrifugal fan of air conditioner

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view of a humidifier, which is an air conditioner according to Embodiment 1 of the present invention, as viewed from the front side of a case.

  The humidifier according to the present embodiment is covered with a main body case 1 having a width dimension W larger than a depth dimension L. The side surface of the main body case 1 is covered with a case front surface 1a, a case side surface 1b on the other side, a case back surface 1c, and a case side surface 1d on one side. The top surface of the main body case 1 is covered with a blower-side top surface 1e that is a top panel that covers the upper part of the space on the other side, and a tank-side top surface 1f that covers the upper part of the space on one side. It has an oval shape in plan view.

  The blower outlet 10 is formed in the ventilation side top | upper surface 1e. The blower outlet 10 is provided in U shape along the outer edge of the ventilation | gas_flowing top surface 1e other than the outer edge which contacts the tank side top surface 1f.

  FIG. 2 is a perspective view of the humidifier as seen from the back side of the case. The humidifier is provided with a suction port 17 over the entire width of the case back surface 1c. The suction port 17 is divided into an upper suction port 15 and a lower suction port 16 in the vertical direction.

  FIG. 3 is a longitudinal sectional view of the humidifier. The humidifier includes a blower 8, a water storage container 11 for storing water, a humidifying filter 12 for absorbing water from the water storage container 11, and a water supply tank 13 for supplying water to the water storage container 11 inside the main body case 1. Yes.

  The air blowing means 8 is disposed in the space a on the other side of the main body case 1. The water supply tank 13 is disposed in the space b on one side of the main body case 1. The space b on one side forms a storage space for the water supply tank 13.

  The air blowing means 8 includes a cylindrical member 8b constituting a fan air inlet 8a, a centrifugal fan 8c, and a motor unit 8e. Therefore, the centrifugal fan 8c rotates by driving the motor unit 8e.

  The air blowing means 8 has a motor intake 8e attached to the lower surface of the air blowing top surface 1e with the fan air inlet 8a facing downward. The motor unit 8e is disposed at the center of the blower-side top surface 1e, and the air outlet 10 shown in FIGS. 1 and 2 is disposed on the blower-side top surface 1e other than the position where the motor unit 8e is disposed in plan view. Yes.

  An air guide tube 9 is provided below the air blowing means 8. The air guide tube 9 forms a central communication port 2 that guides humidified air to the fan intake port 8a. A partition 3 is formed on the outer periphery of the central communication port 2.

  The air guide tube 9 is a tube shape having an arcuate outer peripheral surface, is formed in a shape that further expands downward, is located in an upper space d that is a space below the air blowing means 8, and is located on the other side. It is located at the center of the horizontal plane of the space a.

  The space a on the other side is divided into a lower space c and an upper space d by the partition portion 3. The upper space d is formed on the outer periphery of the air guide tube 9. The lower suction port 16 opens to the lower space c, and the upper suction port 15 opens to the upper space d.

  Between the space a on the other side of the main body case 1 and the space b on the one side of the main body case 1, an inner plate 6 is disposed in the vertical direction. The inner plate 6 is provided between the top surface of the main body case 1 and the partition portion 3. Therefore, the inner plate 6 partitions the air passage of the air blowing means 8 and the space b on one side. The inner plate 6 partitions the upper space d and the space b on one side. The lower space c and the space b on one side communicate with each other.

  The water storage container 11 is arrange | positioned at the space a lower part of the other side, and the space b lower part of one side. The water storage container 11 is configured by a tray that opens upward and stores water at a constant water level from the lower part of the lower space c to the lower part of the space b on one side that serves as a storage space for the water supply tank 13.

  In the water storage container 11 located in the lower space c, a frame-shaped humidifying filter 12 opened in the vertical direction is placed with its lower part immersed in water and its upper end abutting around the central communication port 2. ing.

  The space b on one side is formed below a tank side top surface 1 f formed on the top surface of the main body case 1, and stores a water supply tank 13 for supplying water to the water storage container 11. The water supply tank 13 is inserted into the space b on one side with the tank-side top surface 1f opened, and is detachably attached to the opening of the water storage container 11 provided.

  The water storage container 11, the humidifying filter 12, and the water supply tank 13 constitute a humidifying means 14.

  The operation of the humidifier will be described. When the centrifugal fan 8c rotates by the motor unit 8e, air is sucked from the suction port 17 of the main body case 1 and blown to the humidifying filter 12. Since the humidification filter 12 sucks up water supplied from the water supply tank 13 to the water storage container 11, the air blown here is humidified, and the humidified air is blown into the room from the outlet 10.

  The characteristic point in this embodiment is the structure of the centrifugal fan 8c. FIG. 4 is a perspective view of the centrifugal fan 8c of the humidifier according to Embodiment 1 of the present invention. FIG. 5 is an exploded perspective view of the centrifugal fan 8c of the humidifier according to Embodiment 1 of the present invention. The centrifugal fan 8 c includes a first blade portion 18 and a second blade portion 19.

  The first blade portion 18 includes a main plate 21, a rotating shaft fixing portion 20, and a blade 22. The main plate 21 has a substantially disc shape, and a central portion is convex upward, and a cylindrical rotary shaft fixing portion 20 is provided at the central portion. The rotating shaft fixing unit 20 has a structure in which the rotating shaft of the motor unit 8e is inserted and the rotating shaft can be fixed. At the peripheral edge of the main plate 21, there are a plurality of blades 22 whose horizontal cross-sectional shape extending upward from the main plate 21 has a wing shape. The main plate 21, the rotary shaft fixing unit 20, and the blades 22, which are the first blade portions 18, are integrally formed of a resin material.

  The second blade portion 19 includes a shroud 23 and a blade fixing portion 24. The shroud 23 is an annular first ring portion 25 having a cylindrical shape, and a second ring having a curved cross-sectional shape extending outward and obliquely downward from the lower end edge of the first ring portion 25. Part 26. The second ring portion 26 includes a plurality of blade fixing portions 24 that protrude from the inner surface of the second ring portion 26, that is, extend downward from the lower surface. The plurality of blade fixing portions 24 are provided at positions facing the plurality of blades 22 extending upward from the main plate 21. As for the 2nd blade | wing part 19, the 1st ring part 25 which is the shroud 23, the 2nd ring part 26, and the blade | wing fixing | fixed part 24 are integrally formed with the resin material. When the plurality of blades 22 are fixed to the plurality of blade fixing portions 24, the shroud 23 is disposed to face the main plate 21.

  A fixing structure between the blade 22 and the blade fixing portion 24 will be described.

  The front end of the blade 22 has a first flat end portion 27, a second flat end portion 28, and a connecting end portion 29. The first flat end portion 27 is located on the outer peripheral side of the main plate 21 and is a horizontal surface that can be obtained by horizontally cutting the blades 22. The thickness of the first flat end portion 27 is from the outer peripheral side of the main plate 21 to the main plate. As it goes to the center of 21, it grows. A connecting end 29 extends from the inner end of the first flat end 27 toward the center of the main plate 21. The connection end 29 includes a vertical connection end 30 and an inclined connection end 31. The vertical connection end 30 is a vertical surface extending in the vertical direction from the inner end of the centrifugal fan 8 c of the first flat end 27. The inclined connection end portion 31 is an inclined surface that extends obliquely upward from the inner end of the centrifugal fan 8 c of the vertical connection end portion 30. A second flat end 28 extends from the inner end of the vertical connection end 30 toward the center of the main plate 21. The second flat end portion 28 is located on the center side of the main plate 21 with respect to the first flat end portion 27 and the connecting end portion 29 and is a horizontal surface that can be obtained by horizontally cutting the blades 22. That is, the connecting end portion 29 is positioned between the first flat end portion 27 and the second flat end portion 28 and connects the first flat end portion 27 and the second flat end portion 28. The first flat end 27 is provided with a welding protrusion 27 a that is a protrusion having a horizontal step surface that is slightly smaller than the horizontal surface of the first flat end 27.

  FIG. 6 is a perspective view of blade fixing portion 24 of centrifugal fan 8c according to the first embodiment of the present invention.

  FIG. 7 is an enlarged view of the blade 22 and the blade fixing portion 24 before welding of the centrifugal fan 8c according to the first embodiment of the present invention. FIG. 8 is an enlarged view of the blade 22 and the blade fixing portion 24 after welding of the centrifugal fan 8c according to the first embodiment of the present invention.

  The blade fixing part 24 includes a convex part 32, a first support part 35, and a second support part 36. The convex portion 32 is a hollow projection that protrudes downward from the lower surface of the second ring portion 26. When viewed from the upper surface of the second ring portion 26, the convex portion 32 has a groove shape into which a right-angled triangular plate enters from the upper surface of the second ring portion 26. At the lower end of the convex portion 32, there is a first horizontal flat surface portion 33 that is a horizontal plane, and a connecting surface portion that extends from the inner end of the first horizontal flat surface portion 33 to the center side of the shroud 23 is provided. The connecting surface portion is a first vertical flat surface portion 34 that is a vertical surface extending in the vertical direction from the inner end of the first horizontal flat surface portion 33. The first horizontal flat surface portion 33 and the first vertical flat surface portion 34 are connected at a right angle.

  Elongated protrusions extending in the vertical direction with respect to the first horizontal flat surface portion 33 and the first vertical flat surface portion 34 from the end surfaces on one side of the first horizontal flat surface portion 33 and the first vertical flat surface portion 34, respectively. The first support part 35. Similarly, the other ends of the first horizontal flat surface portion 33 and the first vertical flat surface portion 34 extend in a direction perpendicular to the first horizontal flat surface portion 33 and the first vertical flat surface portion 34. The elongated protrusion is the second support portion 36. In other words, the first horizontal flat surface portion 33 and the first vertical flat surface portion 34 are provided between the first support portion 35 and the second support portion 36. The tip of the blade 22 enters between the first support portion 35 and the second support portion 36. There is a gap between the first support part 35 and the blade 22 and between the second support part 36 and the blade 22, and this gap is larger than the width of vibration caused by ultrasonic waves described later. is there.

  In the above configuration, when the tip of the blade 22 is inserted between the first support portion 35 and the second support portion 36, the first support portion 35 and the second support portion 36 cause the first of the blade 22 to 1 flat end portion 27 and vertical connection end portion 30 which is at least a part of connection end portion 29 are sandwiched.

  Furthermore, it inserts until the welding protrusion 27a of the 1st flat edge part 27 of the blade | wing 22 contacts the 1st horizontal flat surface part 33 of the convex part 32. FIG. In this state, the welding projection 27a is caused to vibrate by ultrasonic waves in the horizontal direction while pressing the first horizontal flat surface portion 33 of the convex portion 32 against the welding projection 27a of the first flat end portion 27 of the blade 22. The blades 22 and the convex portions 32 are welded by 27a being melted and then solidified. This is ultrasonic welding.

  Here, since the space portion 37 is provided between the vertical connection end portion 30 of the blade 22 and the first vertical flat surface portion 34 of the convex portion 32, the vertical connection end portion 30 and the first vertical flat surface portion. No contact with 34. The distance between the vertical connection end 30 of the blade 22 and the first vertical flat surface portion 34 of the convex portion 32 is larger than the distance moved by vibration generated when ultrasonic welding is performed.

  As described above, when ultrasonic welding is performed, the vertical connection end portion 30 that is the connection end portion 29 of the first blade portion 18, and the first vertical flat surface portion 34 that is the connection surface portion of the second blade portion 19. Since the first blade portion 18 and the second blade portion 19 are in contact with each other only in the horizontal plane, a force is exerted in the direction of the rotation axis on the blade 22 extending from the main plate 21. Even if it is vibrated in the horizontal direction, the balance of the centrifugal fan 8c can be improved by suppressing the warpage of the blades 22 and reducing the deformation of the main plate 21 and the shroud 23.

Further, the first horizontal flat surface portion 33 of the convex portion 32 of the shroud 23 is provided with a surface portion side protrusion portion 38 extending downward from the first horizontal flat surface portion 33, and the first flat end portion 27 of the main plate 21 is provided on the first flat end portion 27. Is
An end portion side cutout portion 39 into which the surface portion side projection portion 38 is fitted is provided. The surface portion side projection portion 38 is provided at the inner end portion of the blade 22 of the first horizontal flat surface portion 33. The height of the surface-side protrusion 38 is smaller than the depth of the end-side notch 39 and larger than the height of the welding protrusion 27a.

  An end surface on the inner side of the blade 22 of the surface portion side protrusion 38 is a surface portion protrusion inner end surface portion 40. An end surface on the inner side of the blade 22 of the end-side notch 39 is an end-side notch inner end surface 41.

  A space 37 is provided between the surface-side protrusion inner end surface portion 40 and the end-side notch inner end surface portion 41.

  An outer end surface of the blade 22 of the surface-side protrusion 38 is the surface-side protrusion outer end surface 42.

  An end surface on the outer side of the blade 22 of the end-side notch 39 is an end-side notch outer end surface 43.

  The surface-side protrusion outer end surface portion 42 and the end-side notch outer end surface portion 43 are inclined outward in the blade 22 from the lower end toward the upper end. Here, when the first flat end portion 27 of the blade 22 and the first horizontal flat surface portion 33 of the convex portion 32 come into contact with each other, the surface portion side protrusion outer end surface portion 42 and the end portion side cutout outer end surface portion 43 come into contact with each other. It is the structure to do.

  The ultrasonic welding in the above configuration will be described.

  First, the welding protrusion 27 a of the first flat end portion 27 of the blade 22 is inserted until it comes into contact with the first horizontal flat surface portion 33 of the convex portion 32. In this state, since the space portion 37 is provided between the surface side protrusion inner end surface portion 40 and the end portion side notch inner end surface portion 41, the surface portion side protrusion inner end surface portion 40 and the end portion side notch inner end surface portion 41 are in contact with each other. do not do. Since the first flat end portion 27 and the first horizontal flat surface portion 33 are separated from each other in the height of the welding projection 27a, the surface side protrusion outer end surface portion 42 and the end portion side notch outer end surface portion 43 are also in contact with each other. Not done.

  In this state, when the first horizontal flat surface portion 33 of the convex portion 32 is pressed against the welding projection 27a of the first flat end portion 27 of the blade 22 and is vibrated in the horizontal direction, the welding projection 27a and the first projection Only the horizontal flat surface portion 33 vibrates while contacting. This vibration melts the welding protrusion 27a.

  Next, when the welding protrusion 27a is melted, the first flat end portion 27 of the blade 22 and the first horizontal flat surface portion 33 of the convex portion 32 approach each other, and there are a plurality of surface-side protrusion outer end surface portions 42 and end portions. At least one of the side cutout outer end surface portions 43 comes into contact with the side cutout outer end surface portion 43 to determine the position. When the vibration is stopped here, the melted welding protrusion 27a is solidified, and the blade 22 and the convex portion 32 are welded.

  That is, the surface side protrusion outer end surface portion 42 and the end portion side notch outer end surface portion 43 are inclined outward from the lower end toward the upper end, and therefore vibration until the welding protrusion 27a is melted. Sometimes, the contact between the surface side protrusion outer end surface portion 42 and the end portion side notch outer end surface portion 43 can be suppressed, and when the welding protrusion 27a is melted, the first blade portion 18 and the second blade Positioning with the part 19 is performed. As a result, the balance of the centrifugal fan 8c can be improved by suppressing the warpage of the blades 22 and reducing the deformation of the main plate 21 and the shroud 23.

  In addition, the outer surface of the shroud has a first flat groove surface portion 44, and the first flat groove surface portion 44 faces the first horizontal flat surface portion 33 and faces the first support portion 35. is there. That is, when viewed from the upper surface of the second ring portion 26, the outer surface, that is, the upper surface of the shroud has a groove shape in which the convex portion 32 enters the right triangle plate from the upper surface of the second ring portion 26. The bottom surface of the groove shape is the first flat groove surface portion 44. When ultrasonic welding is performed, a jig (not shown) enters the first flat groove surface portion 44, and simultaneously presses the first horizontal flat surface portion 33 and the first support portion 35, The horizontal flat surface portion 33 is pressed against the first flat end portion 27. That is, since the first flat groove surface portion 44 has a larger area in the thickness direction of the groove shape than the first flat end portion 27 by the first support portion 35, the first horizontal flat surface portion can be stably provided. 33 can be pressed against the first flat end 27. Further, the thickness of the jig can be increased, and as a result, the durability of the jig can be improved.

  According to the present invention, the centrifugal fan includes a first blade portion and a second blade portion, and the first blade portion includes a main plate to which the rotation shaft is fixed, and a plurality of members extending from the main plate. A first flat end located on the outer peripheral side of the main plate and a connecting end extending from the inner end of the first flat end toward the center of the main plate. The second blade portion includes an annular shroud disposed to face the main plate, and a fixing portion that fixes the blade protruding from the inner surface of the shroud. A hollow-shaped convex part, a first supporting part and a second supporting part that extend from the convex part and sandwich the first flat end part of the blade and at least a part of the connecting end part, 1st water which can contact the said 1st flat edge part provided between these 1st support parts and 2nd support parts A flat surface portion and a connecting surface portion extending from the inner end of the first flat surface portion toward the center side of the shroud, the connecting end portion of the first blade portion, and the second blade portion. A space portion is provided between the connecting surface portion and the first flat end portion is provided with a welding protrusion protruding from the first flat end portion, and the welding protrusion and the second blade portion are provided. Vibrating in the horizontal direction with ultrasonic waves while contacting the first flat surface portion, once melting the welding projection of the first flat end portion of the first blade portion, The first flat end portion and the first flat surface portion of the second blade portion are welded by the welding protrusion.

  As described above, the space portion is provided between the connection end portion of the first blade portion and the connection surface portion of the second blade portion, and the first flat end portion includes the first flat end portion. A welding projection projecting from the first projection, and the welding projection and the first flat surface portion of the second blade portion are brought into contact with each other to vibrate in a horizontal direction by ultrasonic waves, and the first blade portion The welding protrusion of the first flat end portion is once melted, and the first flat end portion of the first blade portion and the first flat surface portion of the second blade portion are welded by the welding protrusion. Therefore, when joining the first blade part and the second blade part by ultrasonic welding, even if it vibrates in the horizontal direction while applying a force in the rotational axis direction to the blade extending from the main plate, Since the first blade portion and the second blade portion are in contact with each other only in the horizontal plane, the warpage of the blade is suppressed, and the main plate and By reducing the deformation of the shroud, it is possible to improve the balance of the centrifugal fan.

  Therefore, it is expected to be used for home air conditioners, in particular, humidifiers, humidified air purifiers, and the like.

DESCRIPTION OF SYMBOLS 1 Main body case 1a Case front surface 1b Case side surface on the other side 1c Case back surface 1d Case side surface on one side 1e Blower side top surface 1f Tank side top surface 2 Central communication port 3 Partition part 6 Inner plate 8 Blower means 8a Fan inlet port 8b Tube Shaped member 8c Centrifugal fan 8e Motor unit 9 Air guide tube 10 Air outlet 11 Water storage container 12 Humidification filter 13 Water supply tank 14 Humidification means 15 Upper suction port 16 Lower suction port 17 Suction port 18 First blade portion 19 Second blade portion DESCRIPTION OF SYMBOLS 20 Rotating shaft fixing | fixed part 21 Main plate 22 Blade | blade 23 Shroud 24 Blade | blade fixing | fixed part 25 1st ring part 26 2nd ring part 27 1st flat edge part 27a Welding protrusion 28 2nd flat edge part 29 Connection edge part 30 Vertical connecting end 31 Inclined connecting end 32 Protruding portion 33 First horizontal flat surface portion 34 First vertical flat surface portion 35 First support portion 36 second support portion 37 space portion 38 surface portion side protrusion portion 39 end portion side notch portion 40 surface portion side protrusion inner end surface portion 41 end portion side notch inner end surface portion 42 surface portion side protrusion outer end surface portion 43 end portion side notch outer end surface portion 44 1st flat groove surface part

Claims (4)

Consists of a first blade portion and a second blade portion, and the first blade portion is composed of a main plate to which the rotation shaft is fixed and a plurality of blades extending from the main plate. Has a first flat end located on the outer peripheral side of the main plate, and a connecting end extending from the inner end of the first flat end toward the center of the main plate, and the second The blade portion includes an annular shroud disposed to face the main plate and a blade fixing portion that fixes the blade protruding from the inner surface of the shroud. The blade fixing portion includes a hollow convex portion, A first support part and a second support part extending from the convex part and sandwiching the first flat end part of the blade and at least a part of the connection end part, and the first support part and the first support part A first horizontal flat surface portion that can contact the first flat end portion provided between the first support portion and the first support portion; Consists of a coupling surface portion extending from the inner end of the horizontal flat surface portion toward the center of the shroud, and the connecting end portion of the first blade portion, the space between the connecting surface of the second blade section And the first flat end protrudes from the first flat end, and the first flat end of the first blade portion and the first of the second blade portion. centrifugal fan, characterized in that the horizontal flat surface portion provided with welding projections and ultrasonic welding. The first horizontal flat surface portion of the shroud is provided with a surface portion side protrusion extending from the first horizontal flat surface portion, and the surface portion side protrusion is inserted into the first flat end portion of the main plate. An end portion that is provided with an end-side notch, and that is an end surface on the inner side of the blade on the end portion side notch, and an inner end surface portion on the end portion on the blade side of the end portion notch portion. A space portion is provided between the inner side surface portion of the side-side notch, and an outer end surface portion of the surface-side projection that is an outer side end surface of the blade on the side surface-side protruding portion; An end-side cutout outer end surface portion that is an end surface on the side is inclined outwardly from the lower end toward the upper end, and the first horizontal flat surface portion and the first flat end portion Contact, the surface portion side protrusion outer end surface portion and the end portion side cutout outer end surface portion, Centrifugal fan according to claim 1, characterized in that contact. The outer surface of the shroud has a second flat surface portion, the second flat surface portion is opposed to the first flat surface portion, and the first support portion and a part of the second support portion. The centrifugal fan according to claim 2, wherein the centrifugal fan is opposed to the centrifugal fan. An air conditioner comprising the centrifugal fan according to any one of claims 1 to 3.

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